She began her astronaut training in 1984, and in 1990 was designated a prime Payload Specialist for the first International Microgravity Laboratory Mission (IML-1). Dr. Bondar flew on the NASASpace Shuttle Discovery during Mission STS-42[?], January 22-30, 1992, during which she performed experiments in the Spacelab.

Dr. Bondar left the Canadian Space Agency in 1992 to pursue her research.